NEW DATA ON ICHTHYOFAUNA OF RIVER ESMA (CENTRAL CROATIA)

During the period between April and October 2006 we conducted extensive research on ichthyofauna of river esma in order to extent the knowledge of the freshwater fish fauna of Bjelovar–Bilogora county (central Croatia). We confirmed the presence of 25 fish species sorted in 8 families. Most numerous family was Cyprinidae with 16 species and Percidae with 3, while the remaining 6 families were represented by only one species. According to the proportion in the total individual number, the most abundant were Gobio obtusirostris (13.8%), Rutilus rutilus (12.4%), Rhodeus amarus (11.8%) and Carassius gibelio (11.3%). In the terms of total fish weight (ichthyomass), highest represented was Carassius gibelio (49.5%), followed by Silurus glanis (6.1%), Squalius cephalus (5.4%), Ameiurus melas (4.7%) and Leuciscus idus (4.1%). As there are no previously published data, all 25 species have been recorded for the first time for the river esma basin, while Leuciscus idus and Phoxinus phoxinus have also been recorded for the first time in Bjelovar–Bilogora county